Chicago Bike Blog

Getting to know your bicycle

By guest writer Angela Chan

I remember the first time I learned how to fix a flat, about 5 years ago.  I used to see bicycles as mysterious machines, believing I had no place trying to fix anything on it.  I knew the very, very basics--how to fill my tires with air, and remove the wheels and seat.  I’m not sure I even knew there was a tube inside the tire. 

I didn’t know there was such thing as chain lube, so when I figured out the squeaky noise was coming from my dry and rusty chain, I used vegetable oil to get the squeak out (which I don’t recommend at all now!).  After repairing my first flat, I felt great.  My hands hadn’t been so dirty since art school and they kinda hurt from getting a tough tire back on the rim but I didn’t care.  I didn’t have to go out of my way to a bike shop, I saved some money, and it was rewarding and fun. 

Bicycle maintenance classes are now underway at Rapid Transit Cycleshop.  And I think I speak for myself and my co-workers, when I say that we’re pretty excited to share our knowledge with those wanting to learn. So far, we’ve done classes on basic repair, complete tune-up, wheels and brakes.  We’ve had great students who are willing to learn and ask lots of questions.  

But truthfully, we would love to see more students.  If you love your bike, I do think it’s beneficial to learn how to assess its condition  I still use the assessment techniques I learned from a class years ago, and they have been invaluable.  Recognizing that there’s something wrong early on prevent a more costly repairs down the road, and, most importantly, might prevent you from getting into an accident. 

I know not everyone wants to get their hands dirty, or maybe some of you don’t have the time or inclination,  and prefer to let a professional does the work.  That’s fine too.  Even if you ultimately decide not to work on your own bike after a class or two, you will surely have  gained a better understanding of how your bike works, and more appreciation for the work your bike mechanic does to keep it running smoothly. You’ll be supporting your friendly local bike shop, just like I support the sewing machine or vacuum repair shops.

If you’re new to bikes and want to learn but don’t know where to begin, the Free Roadside Class is a good start.  We’ll demonstrate some basic repairs, assessment techniques and offer up some tips about winter riding.  And did I mention it’s free? 

If you’re a little bit more experienced or ambitious, and are willing to shell out a little moola, the focus classes and tune-up classes will allow you to work on your own bike more intensely.  Winter is great time to learn how to work on your bike, whether or not you ride through the cold season.  If you don’t, you’ve got several months of working on your skills and tinkering to get your bike in tip top shape for the Spring.  If you do cycle through the cold and snow, your bike will need the most attention in the Winter. The salt, moisture and the potholes that pop up throughout the winter take quite a toll on bicycles.  

For me, fixing that first flat was a revelation. 

It was a similar feeling that I had when I first biked (after not cycling for 6 years) with my boyfriend from his place in Lincoln Square to Working Bikes—about an 8 mile trip.  I had realized that there was really no place in the city I couldn’t get to by bicycle.  And with my first flat fix, it occurred to me that, potentially, there was no part of my bike I couldn’t work on.  I was looking forward to getting to know my bicycle.  I’m not a mechanic, but 5 years later, I’m proud to say that I’ve worked on every part on my bicycle, including building the wheels.  I can’t believe the amount of appreciation and respect I’ve gained for this humble machine since my first flat fix. 

We invite you, too, to get to know your bicycle. The complete class listing and schedule is posted on the shop's website, at www.rapidtransitcycles.com. 

Angela Chan is a Sales Person at Rapid Transit Cycleshop.

Rapid Transit Winter Tune-Up is Back

Remember this? Remember the havoc it wreaks on your bike?

That's why Rapid Transit Cycleshop offers it's annual Winter Tune-Up special to Chicago's winter cyclists.

This winter special is more than just a tune-up. It is a season-long maintenance package. It includes all of the goodies that are part of our regular Deluxe Tune-Up, namely:

• Full adjustment of braking system, including pads, levers, cable & housing replacement & lubrication.
• Full adjustment of shifting system, including derailleurs, levers, cable & housing replacement & lubrication.
• External adjustment of both hubs.
• Spot-truing of both wheels as needed to ensure good braking.
• External adjustment of headset.
• External adjustment of bottom bracket.
• Full check of parts and accessories to ensure safety.
• Chain lubrication.
• Tires inflated to correct pressure.
• Free installation on additional accessories purchased from us.
• Complete wheel dishing  & truing. (We will also include inner tube replacement, if needed.)
• Complete drivetrain cleaning or replacement (as needed). There is a lot of variation here, depending on the needs of each individual bike & rider, so please call for details, or better yet, bring you bike in and discuss the repair with the mechanic. Labor assessments and estimates are always free.

But what makes the Winter Tune-Up worthy of its name is the ongoing maintenance we include in this service for the entire cold riding season, specifically until March 31, 2009. After you have purchased your Winter Tune-Up you are entitled to:

• Full bike wash and lube, as often as you wish (normally, $35 each time!)
• Adjustments and tuning whenever needed
• Free labor on fixing flats
• Free installation of parts and accessories purchased at Rapid Transit.

All our offerings also include a thorough evaluation, professional expertise of a mechanic who is also a rider, a burning desire to make your bike work well for you, a test ride to make sure what has been promised is delivered.

You can purchase the Winter Tune-Up for $155 for your multi-speed bike. Please call for pricing on single-speed and fixed-gear bikes

How to change a tube & tire on a bike

Before you begin changing a flat on your bike, you will need to remove the wheel from the frame. Click here for instructions on removing a wheel on a typical hybrid bike.

Chances are your tire has gone flat all the way. If not, unscrew the valve cap, and release any remaining air by pressing down on the valve core. If you have Schrader valves, press the valve core with a pointed object, as shown.

If you have Presta valves, loosen the tip of the valve, and press down on it with your finger. Then unscrew and remove the retaining ring from around the valve, as shown in the photos below.

You will now remove the tire from the rim. Begin by sliding one tire lever between the rim and the tire bead, with the curved end of the tire lever pointing down into the rim.

Repeat with a second tire lever, keeping the two levers 3-4 inches apart. Using the thumbs of both hands, flip the levers up and over, so that they are lying flat against the spokes, and the bead of the tire has been pried off the rim.

Secure one of the tire levers in place by hooking it around the nearest spoke, as shown.

Slide the other tire lever against the rim all the way around, until one bead is completely off the rim. If this is initially difficult, place the wheel vertically on the floor, and lean on the tire lever using the force of your entire arm. As more of the bead comes off the rim, it will become easier.

Pull the damaged tube completely out of the tire.

Some people advocate leaving the other bead on the tire on the rim. While this does make reinstalling the tire easier, I believe it does not allow you to thoroughly inspect the tire to identify the cause of the flat. Therefore, I recommend that you yank the tire completely off the rim, which should be fairly easy to do at this point.

Now take your pump or compressor, and begin filling the damaged tube to observe where the air is escaping. Inspect the tube, the inside and outside of the tire, and the inside of the rim to try to identify the cause of the puncture (click here for details).

Once you have identified and removed the cause of the puncture, you are ready to install the new tube. Put a little air inside the tube, just enough to give it shape, and insert it into the tire. A little air helps the tube stay put inside the tire.

Position the rim with the valve hole toward you. Lay the tire with the tube inside it on top of the rim, and insert the valve into the valve hole.

Go all the way around the rim, and insert only the bottom section of the tire bead into the rim. Do not start on the top section of the bead until the bottom part is mounted all the way around.

When you get to the end of the bottom section of the bead, you may find it easier to pry it into the rim using your tire lever. You may also wish to release some air from the tube at this point by pressing down on the valve core. This will reduce the tension on the tire.

Make sure one side of the tire bead is completely seated around the rim before proceeding to the other bead.

Begin pushing the top portion of the tire bead into the rim, starting at the valve.

Work the top bead in all the way around the rim using your thumbs or the heels of your hands. Some tires will go in fairly easily.

If yours does not, use the tire levers to get the last 3-4 inches of the bead seated, as shown.

(NOTE: Some tire and rim combinations make an extremely tight fit, and even a skilled mechanic has to struggle to get the tire properly mounted. If you find that to be the case with your bike, by all means, look into getting  a different set of tires that will allow you to change a flat with less difficulty.)

Before inflating the tire, make sure the tube is securely encased inside the tire, and not being pinched between the tire bead and rim at any point.

Inflate the tire to the recommended pressure (embossed on the tire sidewall), reinstall the wheel, and you are ready to roll!

Your flat repair kit

Getting a flat is pretty darn inconvenient. Don't make it any more so by leaving your flat changing essentials at home. Here is what you need to be able to change a flat anywhere:

• Spare tube. Make sure that it is the right size and valve type for your bicycle. Not all types of holes can be patched, and replacing a punctured tube with a brand new one is simply faster and more practical than patching a tube on the curb. You can patch the old one at home, if it is salvageable.
• Patch kit. Regardless of what I just said, you should carry patches. Occasionally, a brand new tube may leak air, or you may get a second flat because you haven't properly identified the cause of the original puncture.
• Tire levers. These are essential for removing the tire from the rim. Please don't use a screwdriver; it can damage not only the tube, but the tire and rim as well.
• Portable pump suitable for use with the type of valve you have. Usually, the smaller the pump, the longer it will take to fill up the tire, but even a very small pump is better than nothing.
• A wrench, if your bike does not come with quick release wheels. Generally, 14 and 15 mm wrenches are needed loosen nuts on front and rear wheels, but an adjustable wrench will do in a pinch.
• Just in case: cell phone and money. Carry those whenever you are more than walking distance from home.

Most importantly, practice changing a flat before you leave home. If you come to Rapid Transit to have your flat fixed during non-peak hours, we often have time to show you how it's done. But it is usually not enough to be shown: you have to practice it yourself.

Coming up: step-by -step tube changing tutorial.

Schrader and Presta valves

"How the *bleep* do I fill this up?"

If you have to ask, chances are your bike is not equipped with this type of valve:

This is a typical Schrader valve, found not only on the majority of bicycles, but also familiar to anyone who's ever filled up a car tire. If the tire is low, simply apply the head of any pump or gas station compressor firmly to the tip of the valve, and blow.

But don't take it for granted that your bike comes equipped with the common Schrader valve. You may have to spend some more quality time with your valve if it looks anything like this:

Meet the Presta valve. This is the one that causes bike riders to throw their hands up in exasperation on the first encounter.

When you remove the cap from the Presta valve, you will see a pointy tip with a small brass ring snugged down around it. To open the valve in order to add or release air, you must loosen this ring by turning it counterclockwise. Don't worry, the ring will not come off. But now the valve is open, and you can test it by pressing on the tip with your finger to release some air.

You'll have to complete one more step to pump air into the tire. With the valve in the open position, as shown, place a Presta adapter on the valve by screwing it onto the tip:

Now you can treat it just like a Schrader valve, and fill it up with any standard air compressor or car pump. When you are done filling the tire, make sure you remove the Presta adapter, and re-tighten the brass ring around the valve tip to keep air from escaping while you ride.

To make your life a little easier, most bicycle pumps available on the market today come with dual or universal heads that allow you to fill up either Presta or Schrader valve without the use of an adapter. Before venturing out, practice using your pump with the type of valve you have, to make sure you will know how to fill up your tire should it go flat on the road.

And, just in case, I recommend carrying a Presta adapter with you. Many times it is easier and quicker to fill up tires with a gas station compressor than a portable pump.

Dealing with flats

I was going to tell you how to change a flat on a bike.
Nothing could be simpler. It takes,  oh, maybe ten minutes.
And then again, if you've never done it before, it could take over an hour.

This lesson was brought home to us, seasoned flat-repairers, recently as Rapid Transit Cycleshop hosted a flat-fixing workshop for some friends and their kids. We were again reminded that before you can teach someone how to fix a flat, there is a whole bunch of other stuff they should know first.
So instead of one post, we'll do a series.
Click on links below for information on:
The anatomy of a bicycle wheel
What causes flats
Types of valves
Your flat-repair kit
Removing and reinstalling the tire and tube

What causes flats?

Have you ever been plagued by recurring flats? You keep fixing the tube, or taking it back to your bike shop, you ride for awhile, and, boom! It goes flat again.

A pile of tubes looms over a mechanic's bench at Rapid Transit, waiting for be recycled.

Let me just say that yes, there are mystery flats. There probably is a cause for them, but it cannot be reasonably identified by either you or the mechanic(s). However, in most cases, people continue to get recurring flats, because the the thing that caused the original flat has not been correctly identified.
When you pull your punctured tube out of the tire, go ahead and overinflate it using your pump or an air compressor, and find the hole where the air is escaping.

Look closely at that hole. Where on the tube is it located: top, side, bottom or at the valve? Is it a single hole, or a double? Is it a tear?
Let's begin by identifying five major types of flats, and we'll go over them and their probable causes in more detail:

1. Outer surface punctures
2. Sidewall punctures or "snakebites"
3. Inner surface punctures
4. Blow outs
5. Valve problems

Outer surface punctures:
As you look at your overinflated tube, you will see a single hole on the outer surface of the tube (the surface that corresponds to to the part of the tire that rolls along the ground). That indicates that a sharp object penetrated the tire and punctured the tube. The object may have fallen out, but just as likely, it is still embedded in the tire. Before replacing the inner tube, run your fingers very carefully along the inside of the tire, feeling for anything sharp that may be protruding. At the same time, examine the outside of the tire for embedded pieces of glass and other debris, and poke them out as you go along (a paper clip or sharp tweezers work well). If your tire feels thin and flimsy, or has a lot of slits from previous contact with glass, consider replacing it with a puncture-resistant tire.

Sidewall punctures:
All tires have their recommended inflation pressure embossed on the sidewall. That number can seem incredibly high, especially if you are used to filling up car tires. Bicycle tires take much higher pressure than any car tire, and generally, the thinner the tire, the higher the recommended pressure. Many people are reluctant to fill their bike tires to recommended pressure, perhaps because they are afraid of blow-ups. As you increase the amount of air in the tire, it gets harder and harder to pump, which can make you feel like you're overdoing it.  Yet, filling up tires to the correct pressure will protect you against one of the most common types of flats: the snakebite.

The cause of this is most often riding on underinflated tires. When you hit a bump in the road, the lower-than-recommended pressure allows the tire to bottom-out against the sharp edge of the rim, and the inner tube becomes pinched in the process. You will recognize a snakebite if  you examine your overinflated tube, and discover two small holes, about 1/4" apart, usually on the side of the inner tube.

Inner surface punctures:
If your overinflated inner tube is losing air from its inner surface (the surface that would have been facing the rim), you will need to examine the inside of the rim, and the tire beads. Typical causes of this type of puncture include: a faulty rim strip, resulting in exposed spoke nipples or sharp rim surfaces, a burr on the inner seam of the rim, or a broken tire bead, with exposed wires digging into the tube.

Blow outs:
Sudden blow outs happen when the tube, instead of being safely encased inside the tire, becomes exposed to the outside world. This can happen if, when changing a flat, or filling the tire, a piece of tube inadvertently gets pinched between the rim and the tire. Sometimes it blows right away, but not always. Similarly, you can get a blow-out is the tire bead isn't correctly seated inside the rim, and the inner tube begins to protrude out. Generally, you will feel thumping for the short distance you may be able to ride.

Blow-outs can also occur when the integrity of the tire becomes compromised, and the tube starts to protrude. This can happen as a result of dry rot, a brake pad, fender or other mis-adjusted part rubbing over the tire, or the bead separating from the tire. Inspect your tires periodically to make sure they are in good condition.

Valve problems:
Occasionally, small amounts of debris get jammed inside the valve, causing it to be stuck in open position and leak air. If used improperly, certain flat-prevention products can have the same effect.

Another type of valve failure can occur when you ride on underinflated tires. Every time you brake, the tube and tire continue to move just a little bit even as your wheel stops. This causes the valve to come through the rim hole at an angle. If this goes on long enough, the valve an separate from the body of the tube at the base.

The anatomy of a bicycle wheel

The majority of bicycle wheels you are likely to encounter are comprised of four parts:

1. The tire.
2. The inner tube.
3. The wheel itself, which includes the hub, spokes and rim. For the purposes of flat repair, we will be talking primarily about the rim.
4. The rim strip.

Let's look at each in more detail:

Tire:
The tire is the firm rubber casing mounted on the rim of the bike. By itself, the tire is incapable of holding air. It is open in the center, and has two rigid and fairly sharp edges that allow it to be mounted onto the rim.

These edges are called "beads". On the majority of wheels, the beads are made of coils of wire encased in protective rubber.
As you ride, the tire rolls over road debris, and may pick up pieces of glass, nails and other sharp objects. Some of these items will penetrate the wall of the tire. Most of these punctures are tiny, and do little or no damage to the tire. The tire does need to be replaced if it develops a gash or tear, has dry rot or cracks along the side, or if there is evidence that the bead is separating from the main body of the tire, or protruding from the rubber casing.
The reason small tire punctures become problematic, is that most often they penetrate through to the inner tube, and cause it to lose air.

Inner tube:
The inner tube is a soft, pliable rubber donut with an air valve on its underbelly that allows air in and out.

Note that a filled inner tube can appear larger than the tire. This is perfectly normal. When encased inside the tire, the tube will not exceed the tire's dimensions. When the tube develops a hole for any reason, it will lose air, and need to be patched or replaced.

Rim:
There are many different types of bicycle rims. In addition to the important function of holding the tire onto the wheel, the rim also serves as the anchor for spoke heads, or nipples. On some rims, spoke nipples rest directly on the inner surface of the rim that comes in contact with the inner tube.

On other types of rims, an extra metal layer separates the spoke nipples from the inner-tube. This metal layer has holes drilled in it for access to the spoke nipples. In either case, the protruding spoke heads, or the edges of the holes drilled in the rim are sharp, and can cause damage to the inner-tube.

Rim strip
To prevent this from happening, the inside of the rim is lined with a rim strip. This can be a snug-fitting rubber strip, or pre-gummed cotton tape that is applied to the rim surface. To do its job, the rim strip has to go all the way around the rim , and cover all the spoke heads or holes (except the valve hole).

If it becomes, torn, worn, or folded over, it is no longer doing the job of protecting you from flats.
Please note that on many brand new bikes, cheap plastic rim strips are often used, which can themselves cause punctures and flats (click here for more).

How to use your 24 gears

I have a dream bike. It's probably not what you think. My dream bike is pumpkin orange, has a svelte steel frame, priest-style handlebars, 700 c wheels, and 5 speeds. You can't buy it anywhere, and whenever I approach our otherwise fine mechanics, they tell me it can't be done, not with a traditional derailleur.
Why not? 
Well, with a single chainring on the front, the chain will fall off. Unless you install a front derailleur. Plus, you can't buy a 5-speed cassette anymore. Anyway, why don't you just get a single-speed bike, they ask.
Cuz I like my knees, and sometimes, I want a little extra help.
Well, then, get a bike with an internally geared hub.
No. They're heavy and I don't like'em.

Without getting too much further into the actual feasibility of making my dream bike, and the pros and cons of internally geared hubs, let me just say that many cyclists are puzzled and frustrated by the number of gears on most standard bicycles available today. Here in Chicago, any number of gears above seven is completely redundant and unnecessary for most riders. It is a rare Chicago cyclist who has ever used all of his or her gears, and usually it was outside the state lines. Yet, not everyone wants a cruiser or a fixie. Some folks just want a basic hybrid to ride around town. Most bikes come factory-equipped with more gears than you can count on your fingers and toes, and few salespeople take the time to explain how to use them correctly. Consequently, many cyclist don't know how to shift gears for maximum benefit.

Surprisingly, when you purchase a 24- (or 21 or 27)-speed bike, you do not get gears 1 through 24. Instead, you get three ranges of eight gears. Here is how it works: most bikes have three front chainrings, attached to the pedal crank (road bikes generally have two chainrings): the small one is easy for climbing; the medium is moderate; and the large one is hard, for riding with wind on your back, or going downhill. These are operated by the front derailleur, controlled by the left shift-lever on your handlebars.

For each of the three chainrings, you get eight (or seven, or nine, depending on your bike) gears from the cassette attached to the rear wheel. These are operated by the rear derailleur, controlled by the right shift-lever. Here, the smallest gear is the hardest, and the largest is the easiest. This can be confusing, because it is the opposite of what happens with the front chainrings.

This arrangement of front and rear cogs gives you eight easy, eight moderate and eight hard gears. In a flat city like Chicago, you will probably be using primarily the moderate gear range. Most of us have a favorite gear or two in which we usually pedal. That's the gear that offers the most efficient cadence when you are moving at a good clip, but not pushing a gear that is too hard, or spinning in a gear that's too easy.

On a derailleur-equipped bike (as opposed to a bike with internal gears housed inside a hub), you must be pedaling in order for the chain to move to another gear. Many bikes have shifter indicators, telling you what gear you are in. But after you've gained some practice, you will be shifting gears by feel.

As a rule, shift gears when the riding conditions change: when changing direction (the wind may now be in your face), when the road slope changes, when you are forced to alter your speed. When you pull up to a red light, shift to an easier gear (using your right shifter), so that when the light turns green, you won't have to stand on the pedals to get going. As you begin to accelerate, shift back up to your preferred gear. Shift to an easy gear in front (the left shift-lever) when you approach a steep incline (rare in Chicago, but it could happen, like when you are going on an overpass), and keep shifting gradually as you scale the hill and the pedaling gets harder. Once at the top, shift back to the harder gear in front to get the most out of your descent.
Other things to remember:

• You don't really get 24 gears on your 24-speed bike, because some gear combinations are to be avoided. When riding in the small (easy) chainring in the front, avoid shifting to the small (hard) chainring in the rear. And vice versa. These positions cause the chain to cross over and subject it to undue stress. You may hear the chain grind as it rubs the front derailleur.
• Avoid shifting under torque. When you need to shift, ease the pressure on the pedals somewhat to release the tension in the chain, and allow it to move to the next cog as you press the shifter. 
• You don't have to shift one gear at a time. Simply move through the range of gears until you get to the one you want, and the chain will follow.

Until I get my dream bike, which I promise to do every year, and invariably put it off when push comes to shove, I will keep using my old workhorse, wearing out the same three cogs on the freewheel.

What is a tune-up?

Is a bicycle tune-up worth the money? Absolutely, when you consider what goes into a properly tuned bike, and how well it will work after the service is completed.

Tune-ups and fees associated with them very from shop to shop, so it's a good idea to compare not only the price, but what is included. The quality of service and the workmanship are also important.

When we perform a Deluxe Tune-Up at Rapid Transit, a bicycle gets the mechanic's undivided attention for 2-3 hours. After going over the bike with you, recommending replacement parts, and writing up the cost of the repair, the mechanic will take your bike through the following procedure:

Cleaning and degreasing (aka. The Bike Spa). Your bike will be soaped and scrubbed from top to bottom. The chain, chainrings, freewheel, derailleurs, brakes and rims will be thoroughly degreased and dried. The chain and other key parts of the drivetrain will be treated with a high-quality lubricant.

The Bike Spa

Drivetrain. People who use their bikes heavily find that parts of the drivetrain need to be replaced periodically. If the chain is worn, no amount of lubrication will restore it to it's original functionality. Sometimes a worn chain contributes to excessive wear on the rear cassette, and, in extreme cases, front chainrings. The labor for servicing and replacing these parts is included in the Deluxe Tune-Up. (More on drivetrain maintenance here).

Wheels. After your bike has been cleaned, we will move on to the wheels. We'll adjust the external tension on the bearings of both wheels, and dish the wheels, which involves centering the rims perfectly on the axle. Finally, we true the wheel by precisely tensioning the spokes to make sure the rims are straight and will stay that way.

Headset and bottom bracket. Next, we adjust the external tension on the bearings inside the headset (between the handlebar and the fork of your bike) and the bottom bracket (inside the shell between the crank arms). These bearings, along with the wheels, take a real beating even during normal riding, and the correct tension on these bearings will maximize their lifespan. Even newer sealed bearing systems require servicing, including making sure that they are properly and securely retained, and some have a degree of adjustability.

Gears and Brakes. This is the most "touchy-feely" part of the tune-up. The mechanic will spend an untold amount of time coaxing these parts into submission (often muttering invectives). If necessary, cables and brake pads will be replaced. The brakes will be aligned with the rims, and "toed" to prevent squeaking. The mechanic will adjust the cable tension and the position of the brake arms to make your rear brake quicker and stiffer, and your front brake a little softer, so you don't go flying over the handlebars when you brake.

Some repairs call for extreme measures...

The mechanic will also replace and/or lubricate the derailleur cables, set the cable tension and adjust positioning and the limit  screws on the derailleus, to make sure the gears are shifting quickly and accurately, and the chain doesn't skip off the cogs.

Safety Check. The mechanic will fill up the tires, and check the safety and secure attachment of all the parts and accessories on you bike, making sure that nothing is worn or loose, or could contribute to an accident or fall.

Test Ride. Finally, the mechanic will test ride your bike to check if all that work paid off. Any problems will be corrected, and then a bike will be double-checked by a second technician.

The tune-up described above is suitable for heavily-used bikes. Lighter versions of the services are available for lighter riders (click).